const mongoose=require('mongoose');
module.exports=new Promise((resolve,reject)=>{
    mongoose.connect('mongodb://localhost:27017/student_2203_2',{useNewUrlParser:true,
    useUnifiedTopology:true,useCreateIndex:true});
    mongoose.connection.once('open',err=>{
        if(!err){
            console.log('数据库连接成功');
            resolve();
        }else{
            console.log(err);
            reject(err);
        }
    })


})